Discharge of bladder contents can be a source of serious and distressing problems for persons whose anatomy is temporarily, or over time, incapable of completely controlling the outflow of urine from the bladder, a clinical condition known as urinary retention. Traditionally, indwelling urethral catheters (i.e., Foley catheters, or the like), in which a free passage is created between the bladder and the outside of the human body in such a way to ensure the permanent flow of urine, have long been used to facilitate bladder drainage in individuals who are unable to initiate or control such drainage due to organic disability, immobility, or other physical impairment, most typically scenarios of acute, rather than chronic, retention. For instance, acute retention is frequently experienced by patients who have recently undergone surgical intervention, either unrelated or related to the urethra. Acute urinary retention is also frequently experienced following radioactive seed implantation within the prostate, cryogenic treatment of the prostate, or minimally invasive procedures performed for the purpose of reducing the volume of the prostate. These include various thermal procedures such as the introduction of microwave energy, heat introduction systems, and chemical injections.
Intraurethral catheters generally permit continuous drainage, or user controlled bladder drainage, with such latter devices typically requiring replacement of, or supplementing the continuous drainage catheter with an incontinence flow control device that enables the user to control bladder discharges through user controlled valves such as those shown, for example, in U.S. Pat. No. 3,812,841 (Isaacson), U.S. Pat. No. 4,909,785 (Burton et al.), U.S. Pat. No. 4,932,938 (Goldberg et al.), U.S. Pat. No. 4,946,449 (Davis, Jr.), and U.S. Pat. No. 5,041,092 (Barwick).
The shortcomings of heretofore known devices have included, but are not limited to, in-situ migration of such devices, a limited indwelling life because of the likely onset of serious urethral infections, and operational complications, most remarkably the cessation of reliable valve functioning, necessitated by the general urinary tract environment (e.g., limited dimensions of the urethra, prolonged device exposure to urine, etc.).
A somewhat related, yet distinct retention solution, in contrast to the traditional indwelling urethral catheter, and those heretofore enumerated urinary flow control devices, has been endourethral stents, or what was initially referred to as the “urological spiral,” first developed by Fabian in or about 1978. Generally, the patency of the prostatic urethra is optimally secured by the spiral shape and elastic construction of a coiled, rust-proof, steel urological spiral element. Although chronic infections of the urinary tract and “valve” failure are avoided, since the physiological “valve” function of the man's urethra remains maintained with use of the urological spiral, device migration, deployment difficulties, and debris accumulation and passage, offset any perceived advantages. Later developed prosthetic devices for stenting portions the lower urinary tract integrated inflatable balloons therewith to facilitate placement and positioning of such prosthesis, with heretofore known examples of such devices disclosed in U.S. Pat. No. 5,766,209 (Devonec), U.S. Pat. No. 5,876,417 (Devonec et al.), U.S. Pat. No. 5,916,195 (Eshel et al.), and PCT/US99/23610 (Lennox et al.).
Devonec '209 provide a device having a sphincter responsive sleeve which is sufficiently flexible to conform to the anatomical profile of the urethra and its movements, yet is sufficiently rigid so as to maintain an artificial passage in the urethra. The device is generally supported in the urethra principally by the elastic bearing of the wall of the device segment in radial extension.
Devonec et al. '417 provide a catheter having a indwelling element comprising upper and lower tubular elements, the lower tubular element having an inflatable balloon which circumscribes it. As is readily appreciated with reference to FIGS. 4–9 of Devonec et al. '417, the inflatable balloon functions solely as a positioning device, the indwelling portion being suitably positioned upon abutment of the striated muscular sphincter by the inflated balloon so as to position the deformable portion of the catheter within the sphincter orifice.
Eshel et al. '195 show an internal catheter having proximal and distal tubular members interconnected by a fluid conduit for inflating a balloon attached to the distal tubular member, the device being deliverable using a guiding element which includes a guide balloon for frictionally retaining the device with respect thereto. Once introduced into the urethra, the device balloon is positioned to be within the urinary bladder, and inflated so as to temporarily anchor the catheter at a required position such that a segment of said tubular member is located at the prostatic urethra. The positioning of one of the tubular members at one side of the sphincter, and the other tubular member at the other side of the sphincter, is alleged to effectively anchor the catheter in place, such that after extraction of the guide element, the device balloon is deflated (i.e., the distal device balloon is used as a locating mechanism, rather than a anchoring mechanism).
Lennox et al. '23610 likewise make use of an inflatable balloon for inserting a prosthesis into the urethra of a patient. More particularly, in the deployment methodology, the prosthesis, the pusher, the inflation cannula, and the balloon are inserted into a urethra of the patient. The prosthesis is pushed by the pusher along with the inflation cannula until a drainage hole of a first tubular element is positioned within the bladder. Thereafter, the balloon is inflated via the inflation cannula, the prosthesis thereafter being withdrawn until resistance is felt. This resistance indicates that the balloon is contacting the opening of the bladder just above the prostate. After appropriate positioning, the deployment apparatus including the balloon may be retracted in furtherance of removal.
Due to a general lack of reliable device performance (e.g., continued device migration, increasing device and deployment complexity, generally cumbersome overall device structure, etc.), heretofore known stenting devices served a single purpose, namely as a retention solution, and did so with a variety of shortcomings. With no reliable, straight forward differential diagnosis options being generally accepted and practiced, males presenting with non-retention symptoms have had no diagnostic options short of invasive irreversible medical procedures (e.g., surgery, thermal treatment, etc.).
Presently, millions of men in the United States alone exhibit some form of lower urinary tract symptoms (LUTS), with bladder outlet obstructions (BOOs), being a major subgroup of LUTS. BOOs are primarily caused by the enlargement of the prostrate gland (e.g., benign prostate hyperplasia (BHP)) which results in radial compression of the urethra surrounded thereby (i.e., the prostatic urethra), thus obstructing (i.e., constricting) urine flow, resulting in incomplete emptying of the bladder (i.e., there being what is clinically referred to as a “post void residual” (PVR) remaining in the bladder). Heretofore, such symptoms would be treated by using surgical procedures such as trans urethral resection of the prostate (TURP), or non-surgical procedures such as thermal treatment of the prostate.
As alluded to herein above, three inter-dependent, easily-measured parameters may be ascertained and assessed in furtherance of increased understanding of the patient's urodynamic status, namely, PVR, volumetric flow (i.e., discharge rate) of urine from the bladder, and voiding pattern(s) readily established via maintenance of avoiding diary (i.e., evaluation of about one week's worth of voiding specifics).
The first parameter, PVR, is determined using ultrasound imaging of the bladder, with a retained urine volume calculated and recorded post void. Although there exist a variety of clinical data on the matter, it is generally believed that a PVR value of about <100 cc is considered a “successful” void, with a PVR value in excess of about 300 cc being cause for serious concern, or at least cause for further inquiry into the subject's void patterns, etc. For example, a subject with an “abnormal” PVR (i.e., symptomatic PVR) will often need to urinate more frequently, and-is likely to experience physical discomfort, such as frequent urges to urinate, as well as physical exhaustion due to sleep deprivation (i.e., nocturia). Symptomatic PVR is typically associated with either hyperplasia (i.e., thickening) of the prostatic gland, or a bladder that is not functioning properly due to decompensation of the muscular function. It is this diagnostic differentiation that has heretofore been unrealized in a simple, straight forward and reliable manner.
The second parameter, urine discharge rate during emptying of the bladder, is a strong indicator of the function of the bladder when obstruction via the prostate is not present. Typical urine discharge rates for “healthy” males is in excess of about 12 cc/s, with a diminished discharge flow rate of about <5 cc/s generally believed to be indicia of BOO.
Due to the fact that BOO patients are only a subgroup of patients with LUTS, proper treatment of the specific problem requires complete knowledge of the urodynamic status of the patient in order determine whether the patient's symptoms are caused by BOO, or from bladder deficiencies (e.g., bladder decompensation), or sphincter dysnergia. While comprehensive knowledge of the bladder-urethra interaction during urination may be obtained using complex urodynamic procedures, and urethra pressure profiling, most urologists are currently reluctant to perform such procedures prior to invasive, or minimally invasive, procedures directed to debulking the prostatic urethra.
Thus there remains a need, in addition to traditional therapeutic application of an improved endourethral device for subjects in retention, for improved diagnostic confidence for LUTS patients, more particularly, a differential diagnostic that is low risk, reliable, and least cost. Accordingly, it is desirable to provide additional, improved device and procedural options for the care and diagnosis of patients who present to the urologist with LUTS, or patients who experience acute retention or chronic retention.